Grading of Emphysema Is Indispensable for Predicting Prolonged Air Leak After Lung Lobectomy

Significance of the Goddard Score in Predicting Complications Related to Air Leak After Lobectomy

BACKGROUND

Postoperative air leakage is a frequent complication after lung resection, and emphysema is a risk factor. However, no study has investigated the relationship between emphysema severity and postoperative complications related to air leak by the Goddard score (GS), a visual evaluation method of radiologic emphysema using computed tomography.

METHODS

This study included patients who underwent lobectomy for non-small cell lung cancer between April 2009 and March 2022. The utility of GS in predicting complications related to air leak (air leak prolonged for ≥5 days, pleurodesis, and reoperation for air leak) was investigated by receiver operating characteristic curve analysis and multivariable analysis with a logistic regression model.

RESULTS

This study included 477 patients. The GS was a significant predictor of complications related to air leak (area under the curve, 0.696; P < .001). Based on the receiver operating characteristic curve analysis, GS of 6 points was used as the cutoff point for multivariable analysis. In the multivariable analysis, GS of ≥6 points was a significant predictor of complications related to air leak (odds ratio, 2.719; P = .007). In the subgroup analysis of patients with emphysema, GS of ≥6 points was a significant predictor of complications related to air leak (P = .014).

CONCLUSIONS

The GS was useful in predicting complications related to air leak. Patients with radiologic findings of emphysema with GS of ≥6 points should be recognized as a high-risk group for complications related to air leak.

Effectiveness of Stitch With Pledget to Prevent Prolonged Air Leak in Thoracoscopic Lung Resection

INTRODUCTION

We previously demonstrated the usefulness of combining stitching with covering to seal alveolar air leaks in an animal model. This study aimed to clarify the effectiveness and feasibility of this sealing method in the clinical setting.

METHODS

Data of 493 patients who underwent thoracoscopic anatomical resection between 2013 and 2020 for lung cancer were retrospectively reviewed. Prolonged air leak was defined as chest drain placement lasting 5 d or longer due to air leak. Until July 2017 (early study period), we covered air leaks using mesh. However, for sealing (late study period), we additionally stitched leaks with pledget in patients at high risk of prolonged air leak. The pneumostasis procedure, intraoperative confirmation test of pneumostasis, and chest tube management were uniform during both periods.

RESULTS

The incidence of prolonged air leak was significantly lower in the late than in the early period (3.6% versus 12.5%), whereas pulmonary emphysema was more severe in the late period compared to the early period. Intraoperative failure of sealing air leaks was significantly reduced in the late period than in the early period. In both univariate and propensity score matching analysis, the study period was a significant predictor of prolonged air leak.

CONCLUSIONS

The combination of stitching and covering with mesh may contribute to reducing prolonged air leak incidence in patients undergoing thoracoscopic anatomical lung resection for lung cancer.

The clinical effectiveness of staple line reinforcement with different matrix used in surgery

Staplers are widely used in clinics; however, complications such as bleeding and leakage remain a challenge for surgeons. To tackle this issue, buttress materials are recommended to reinforce the staple line. This Review provides a systematic summary of the characteristics and applications of the buttress materials. First, the physical and chemical properties of synthetic polymer materials and extracellular matrix used for the buttress materials are introduced, as well as their pros and cons in clinical applications. Second, we review the clinical effects of reinforcement mesh in pneumonectomy, sleeve gastrectomy, pancreatectomy, and colorectal resection. Based on the analysis of numerous research data, we believe that buttress materials play a crucial role in increasing staple line strength and reducing the probability of complications, such as bleeding and leakage. However, considering the requirements of bioactivity, degradability, and biosafety, non-crosslinked small intestinal submucosa (SIS) matrix material is the preferred candidate. It has high research and application value, but further studies are required to confirm this. The aim of this Review is to provide comprehensive guidance on the selection of materials for staple line reinforcement.

Usefulness of free pericardial fat pads as pledgets for air leaks in pulmonary resection

PURPOSE

Intraoperative control of air leaks is important for preventing prolonged air leaks after surgery. The usefulness of suturing free pericardial fat pads (FPFPs) as pledgets for repairing air leaks was investigated.

METHODS

A total of 111 patients who underwent anatomical lung resection and required suture repair for intraoperative air leaks were retrospectively reviewed. Mattress sutures were performed using polyglycolic acid (PGA) sheets (PGA group; n = 60) in the early period (April 2014 to March 2018) and FPFPs (FPFP group; n = 51) in the late period (April 2018 to March 2021) as pledgets.

RESULTS

More patients had a history of smoking in the FPFP group than in the PGA group. The duration of air leakage was significantly shorter (mean 1.2 vs. 3.5 days, p = 0.002) and prolonged air leakage (> 5 days) was less frequently observed (23.3% vs. 5.9%, p = 0.016) in the FPFP group than in the PGA group. The FPFP group had fewer cases requiring pleurodesis and with recurrent air leaks than in the PGA group. In one case in the FPFP group, fat necrosis with fibrosis and fibrous adhesion to the visceral pleura was found on a pathological examination.

CONCLUSION

Parenchymal repair using FPFPs as pledgets can reduce prolonged air leaks after surgery.

Risk factors for prolonged air leak after pulmonary surgery: A systematic review and meta-analysis

This study aimed to comprehensively identify risk factors for the occurrence of prolonged air leak (PAL) in patients undergoing pulmonary surgery. Studies were retrieved from 3 databases, including PubMed, Web of Science, and EmBase up to 13 May 2020. We performed meta-analysis using Bayesian random effect models through divergence restricting conditional tessellation (DIRECT) algorithm. The effect size was expressed as odds ratio (OR) or mean difference (MD), each with 95% credible interval (CrI). The evidence quality was evaluated. Subgroup analyses and sensitivity analyses were conducted. Thirty-nine studies with 89006 patients were finally included. Pooled PAL incidence was 15%. Of 30 risk factors, 22 were significantly associated with increased PAL incidence. Five risk factors were ultimately selected with high evidence quality: smoking history (OR 1.84, 95%CrI 1.45 to 2.31, P<0.001), preoperative steroid use (OR 1.51, 95%CrI 0.87 to 2.65, P = 0.031), lower ratio of forced expiratory volume in 1 s and forced vital capacity (OR 1.99, 95%CrI 1.22 to 3.33, P = 0.005), non-fissureless technique (OR 2.14, 95%CrI 1.31 to 3.66, P = 0.003), and pathological TNM stage III/IV (OR 1.50, 95%CrI 1.07 to 2.12, P = 0.003). Regarding the negative impact of PAL on the personal cost and postoperative recovery, the verification of previous proposed factors and investigation of recently discovered ones both implied directions for risk stratification and the establishment of an applicable prediction model.

Predicting Respiratory Complications Following Lobectomy Using Quantitative CT Measures of Emphysema

Purpose

In performing surgery for lung cancer, emphysema is a risk factor related to postoperative respiratory complications (PRC). However, few studies have addressed the risk of radiological emphysematous volume affecting PRC. The aim of this study was to investigate the relationship between emphysematous volume as measured on 3-dimensional computed tomography and PRC.

Patients and Methods

We reviewed 342 lung cancer patients undergoing lobectomy between 2013 and 2018. The percentage of low attenuation area (LAA%) was defined as the percentage of the lung area showing attenuation of −950 Hounsfield units or lower. Preoperative factors including age, sex, body mass index, smoking index, respiratory function, tumour histology, and LAA% were evaluated. PRC included pneumonia, atelectasis, prolonged air leakage, empyema, hypoxia, ischemic bronchitis, bronchopleural fistula, and exacerbation of interstitial pneumonia. Uni- and multivariable analyses were performed to investigate the relationship between independent clinical variables and postoperative adverse events.

Results

Median LAA% was 5.0% (range, 0–40%) and PRC was observed in 50 patients (14.6%). Patients who presented with PRC showed significantly high LAA% compared to those without complications (median: 8.1% vs 3.8%; p < 0.001). Based on univariable analysis, age, sex, smoking index, percentage of forced expiratory volume in 1 s (FEV_1.0%), histology, and LAA% were significant predictors for PRC. Multivariable analysis revealed higher LAA% as a significant risk factor for PRC (odds ratio = 1.040; 95% confidence interval, 1.001–1.080; p = 0.046).

Conclusion

In addition to respiratory function with spirometry, LAA% can be used as a predictor of PRC.

Predictive factors and economic impact of prolonged air leak after pulmonary resection

OBJECTIVE

Prolonged air leak (PAL) is one of the most common complications after pulmonary resection for lung cancer. This study aimed to identify the factors that predict PAL, and to evaluate the impact of PAL on the development of additional complications and cost of hospitalization.

METHODS

A total of 2278 patients who underwent pulmonary resection other than pneumonectomy for lung cancer from 2014 to 2018 were retrospectively enrolled in this study. PAL was defined as air leak that continued more than 5 days after the operation. Multivariate analyses were conducted to identify significant predictors of PAL, using clinical information. Development of complications other than PAL, and cost of hospitalization care were also analyzed.

RESULTS

PAL was observed in 91 (4.0%) cases. Multivariate logistic regression analysis revealed that the presence of intrathoracic adhesion (odds ratio [OR] 4.476, p < 0.001), smoking history > 20 pack-year (OR 2.441, p = 0.005), male sex (OR 2.269, p = 0.013), and lobectomy or bilobectomy (OR 1.935, p = 0.025) were significant risk factors for PAL. The presence of PAL was related to the development of additional complications (p < 0.001). The cost of hospitalization care in patients with PAL was about 1.3 times higher than that in patients without PAL (p < 0.001).

CONCLUSIONS

PAL is related to additional complications and higher cost of hospitalization care. Surgeons should pay careful attention to minimize the incidence of PAL in patients with risk factors including intrathoracic adhesion, history of heavy smoking, male sex, and lobectomy or bilobectomy.

Efficacy of Alaska pollock gelatin sealant for pulmonary air leakage in porcine models

BACKGROUND

Postoperative prolonged air leakage is a frequent complication following lung resection. We have developed a new sealant based on a hydrophobically modified Alaska pollock-derived gelatin (ApGltn) sealant. The purpose of this study was to evaluate the adhesive strength of the ApGltn sealant in comparison with a fibrin sealant using a new spray system in ex vivo and in vivo models.

METHODS

Pleural defects in ex vivo and in vivo porcine models were created, to which the ApGltn sealant or the fibrin sealant was applied. The pressure resistance was assessed with a stepwise increase in airway pressure to confirm air leakage from the sealing site. Tissue samples covered with each sealant were obtained for histologic assessment.

RESULTS

In the ex vivo experiment, the leak pressures of the ApGltn sealant were significantly greater than those of the fibrin sealant (102.94 ± 15.6 cmH₂O and 28.37 ± 5.1 cmH₂O, respectively) (p < 0.01). In the in vivo experiment, the leak pressures of the ApGltn sealant were also significantly greater than those of the fibrin sealant (68.82 ± 18.04 cmH₂O and 43.33 ± 7.13 cmH₂O, respectively) (p = 0.043). The histologic examination confirmed that the ApGltn sealant adhered tightly to both the pleura and the surface of the pleural defect.

CONCLUSIONS

The ApGltn sealant has sufficiently high adhesive quality in ex vivo and in vivo porcine lungs, which could be considered suitable and effective for use in the prevention of air leakage from the lungs.

Cluster analysis of emphysema for predicting pulmonary complications after thoracoscopic lobectomy

 

OBJECTIVES

Despite significant advances in surgical techniques, including thoracoscopic approaches and perioperative care, the morbidity rate remains high after lung resection. This study focused on a low attenuation cluster analysis, which represented the size distribution of pulmonary emphysema and assessed its utility for predicting postoperative pulmonary complications after thoracoscopic lobectomy.

METHODS

From April 2013 to September 2018, lung cancer patients who received spirometry and computed tomography (CT) before surgery and underwent thoracoscopic lobectomy were included. The cumulative size distribution of the low attenuation area (LAA, defined as ≤-950 Hounsfield unit on CT) clusters followed a power-law characterized by an exponent D-value, a measure of the complexity of the alveolar structure. D-value and LAA% (LAA/total lung volume) were calculated using preoperative 3-dimensional CT software. The relationship between pulmonary complications and patient characteristics, including D-value and LAA%, was investigated.

RESULTS

Among 471 patients, there were 61 respiratory complication cases (12.9%). Receiver operation characteristic curve analysis revealed that the best predictive cut-off value of D-value and LAA% for pulmonary complications was 2.27 and 16.5, respectively, with an area under the curve of 0.72 and 0.58, respectively. D-value was significantly correlated with % forced expiratory volume in 1 s. Per univariate analysis, gender, smoking history, forced expiratory volume in 1 s/forced vital capacity, LAA% and D-value were risk factors for predicting postoperative pulmonary complications. In the multivariate analysis, D-value remained a significant predictive factor.

CONCLUSION

Preoperative assessment of emphysema cluster analysis may represent the vulnerability of the operated lung and could be the novel predictor for pulmonary complications after thoracoscopic lobectomy.

A risk model for prolonged air leak after lobectomy using the National Clinical Database in Japan

PURPOSE

The objective of our study was to develop a clinical prediction model for prolonged air leak (PAL) after lobectomy for lung cancer using preoperative variables in a large patient dataset from the National Clinical Database (NCD) in Japan.

METHODS

The preoperative characteristics of 57,532 and 30,967 patients who had undergone standard lobectomy for lung cancer were derived from the 2014 to 2015 and 2016 NCD datasets, respectively. PAL was defined as air leak persisting ≥ 7 days postoperatively or requiring postoperative interventional treatment, such as pleurodesis or reoperation. Risk models were developed from the 2014 to 2015 dataset and validated using the 2016 dataset. When performing model derivation, the least absolute shrinkage and selection operator (LASSO) method were applied for parameter selection.

RESULTS

The rate of PAL was 4.5% in 2014-2015 and 5.3% in 2016. The age, sex, body mass index, comorbid interstitial pneumonia, smoking habits, forced expiratory volume in 1 s, tumor histology, multiple lung cancer, and tumor location were selected as important variables for PAL. Our risk model for predicting PAL was fair with a concordance index of 0.6895.

CONCLUSION

The LASSO-based risk model for PAL after lobectomy provided important preoperative variables for PAL and risk weighting for each variable.

Use of Stitching and Bioabsorbable Mesh and Glue to Combat Prolonged Air Leaks

Prolonged postoperative air leaks are associated with extended periods of postoperative hospitalization, increased hospital costs, and increased incidence of major cardiopulmonary complications. To prevent prolonged air leaks, we used small pieces of polyglycolic acid mesh as a pledget during the stitching of air leak sites. The stitched sites were then covered with mesh and fibrin glue. This novel technique showed the highest airway pressure tolerance in an ex vivo experimental study. There were no incidents of prolonged air leak among the five clinical cases in which this technique was initially applied. A large-scale study of patients with a high risk of prolonged air leak is warranted.

The everlasting issue of prolonged air leaks after lobectomy for non-small cell lung cancer: A data-driven prevention planning model in the era of minimally invasive approaches

BACKGROUND AND OBJECTIVES

Prolonged air leaks (PAL) are the most frequent complication after lobectomy for non-small cell lung cancer, even in case of minimally invasive approaches. We developed a novel score to identify high-risk patients for PAL during minimally invasive lobectomy.

METHODS

A dedicated database was created. We investigated preoperative candidate features and specific intraoperative variables. Univariate and subsequent logistic regression analysis with bootstrap resampling have been used. Model performance has been assessed by reckoning the area under the receiver operating characteristics curve and the Hosmer-Lemeshow goodness of fit.

RESULTS

PAL (>5 days) occurred in 72 (15.69%) patients. Five variables emerged from the model. Each one was assigned a score to provide a cumulative scoring system: forced expiratory volume in 1 second below 86% (P = 0.004, 1.5 points), body mass index <24 ( P = 0.002, 1 point), active smoking ( P = 0.001, 1.5 points), incomplete fissures ( P = 0.004, 1.5 points), and adhesions ( P = 0.0001, 1 point). The new score provided a stratification into four risk classes.

CONCLUSIONS

The risk score incorporates either general or more specific variables, providing a risk stratification that could be readily applied intra- and postoperatively. Henceforth, specific technical and management measures could be properly allocated to curb PAL.